JP2001260394A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive printer in which print speed can be enhanced while preventing the image quality from deteriorating. SOLUTION: The printer for printing or forming an image on the surface of a recording material by applying ink thereto comprises a color ink head group including an ink head 12 for applying yellow ink to the surface of the recording material, an ink head 11 for applying magenta ink to the surface of the recording material, and an ink head 10 for applying cyan ink to the surface of the recording material, and a black ink head 9 for applying black ink to the surface of the recording material wherein the black ink head 9 is interposed between two ink heads 11, 12 for applying ink of different colors to the surface of the recording material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly, to a printer having a black ink head and a group of color ink heads.

[0002]

2. Description of the Related Art Conventionally, there has been known an image generating apparatus which forms a print or an image by adhering droplet-shaped ink to a surface of paper or the like as a recording material. Inkjet printer).
In such an ink jet printer, a color image can be formed by using not only black ink but also color inks such as cyan ink, magenta ink, and yellow ink. For this reason, the application range of the ink jet printer is expanding to various fields.

[0003] Conventional color ink jet printers
In general, the printer includes a printer head unit held by a carriage. A black ink head that discharges black ink and a plurality of color ink heads that discharge color ink are formed in the printer head unit. Examples of the color ink head include a cyan ink head that discharges cyan ink, a magenta ink head that discharges magenta ink, and a yellow ink head that discharges yellow ink. These ink heads are formed with a plurality of nozzles for discharging normal ink. Then, ink is ejected from the ink head onto the surface of the recording material while the printer head is scanned in a scanning direction substantially parallel to the surface of the recording material such as paper, and the ink adheres to the surface of the recording material. When the scanning is completed, the relative position of the recording material with respect to the ink head is shifted in a direction substantially perpendicular to the scanning direction using a paper feed roller or the like. And
The ink is caused to adhere to the surface of the recording material while scanning the printer head again. By repeating such a process, a desired image can be formed on the surface of the recording material. Further, in such an ink jet printer, in order to increase the printing speed, a bidirectional printing method in which ink is adhered to the surface of a recording material in both forward and backward scanning directions of the printer head is generally used.

Conventionally, the above-described ink head is, as shown in FIGS. 21 and 22, an end of a color ink head group including a cyan ink head (C), a magenta ink head (M), and a yellowing head (Y). A black ink head (K) is arranged in the section. FIG. 21 is a schematic view showing an ink head group of a conventional printer.
7 shows an example of the arrangement of ink head groups in a printer head unit of a conventional inkjet printer. FIG. 22 is a schematic diagram showing another example of the ink head group of the conventional printer.

Referring to FIG. 21, ink head group 113
Are the black ink head 109 and the cyan ink head 110
And a magenta ink head 111 and a yellow ink head 112. As described above, the black ink head 109 is disposed on the left side of the color ink head group including the cyan ink head 110, the magenta ink head 111, and the yellow ink head 112.

[0006] The types of inks used in the above-described ink jet printers mainly include pigment inks and dye inks. The pigment ink-based black ink (pigment black ink) is generally used because of its superior black color development as compared with the dye ink-based black ink (dye black ink). However, the pigment black ink is inferior to the dye black ink in the drying property and the permeability to the recording material. For this reason, when the pigment black ink is used, there may be a problem that the quality of the image is deteriorated due to the bleeding of the pigment black ink applied to the surface of the recording material for forming an image.

In order to solve the above problems, for example, Japanese Patent Application Laid-Open Nos. 7-149036 and 8-1978
No. 31 discloses a technique for forming an image by applying a black ink and a dye-based color ink having better drying properties and the like than the black ink on the surface of the recording material, and a technique for forming an image. A technique is disclosed in which the dot density of black ink is reduced in a black print area, and a dye-based color ink is applied to gaps between the dots of the black ink. JP-A-7-149036 and JP-A-8-197831
In Japanese Patent Application Laid-Open No. H11-157, it is possible to improve the drying property of the ink in the black print area by the above-described technique, and thus it is possible to prevent the formed image from bleeding, rubbing, and stains.

[0008]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. 7-1
No. 49036 and Japanese Patent Application Laid-Open No. H8-197831 describe a conventional color ink-jet printer using the ink head group 113 shown in FIG. In the case of using the method, there are the following problems.

That is, when the pigment black ink and the dye color ink are superimposed and printed in the black print area of the image to be formed, the printer head section in which the ink head group 113 is formed is, for example, indicated by an arrow shown in FIG. Forming (printing) an image on the recording material while moving (scanning) relative to the recording material in the direction of 130
Then, the black ink ejected from the black ink head 109 first adheres to the surface of the recording material. Thereafter, color inks such as cyan ink, magenta ink, and yellow ink adhere to the surface of the recording material over the black ink. On the other hand, when an image is formed on a recording material while moving the printer head unit in which the ink head group 113 is formed in a direction of an arrow 131 which is a direction opposite to the arrow 130, an image is formed as described above. Is yellow ink,
A color ink such as a magenta ink and a cyan ink is first applied to the surface of the recording material, and then the black ink is applied to the surface of the recording material in an overlapping manner.

As described above, when the moving direction (scanning direction) of the printer head is different, the order in which the color ink and the black ink are adhered to the recording material surface is reversed. In such an image region where the order in which the color ink and the black ink are applied is different, a difference occurs in the color of the same “black”. For this reason, the area printed while moving the printer head in the direction of arrow 130 and the arrow 1
In the area printed while moving in the 31 direction, a difference occurs in the hue even in the same “black” display. As a result, there arises a problem that the quality of the formed image is deteriorated. Such a problem similarly occurs in an ink jet printer having the ink head group shown in FIG.

As one method for preventing such a difference in color tone, it is conceivable to fix the order in which black ink and color ink are applied to the surface of the recording material (application order). However, in order to fix the application order in this way, when the printer head unit 113 as shown in FIG. 21 is used, when the printer head unit is moved in either the direction of arrow 130 or the direction of arrow 131 Only in this case, it is necessary to perform printing (the ink is made to adhere to the surface of the recording material). As a result, arrows 130 and 131
When the printer head section is moved in both directions, the bidirectional printing method for forming an image cannot be used, so that a problem that the printing speed is reduced occurs.

Further, as described above, in the technique of lowering the dot density of the black ink in the black print area and applying the color ink to the gaps between the dots of the black ink, the above-described application of the black ink and the color ink is performed. I don't think there will be any problems due to the order. However, actually, after the black ink and the color ink adhere (apply) to the surface of the recording material such as paper, the applied ink spreads on the surface of the recording material. The same problem as in the case of overlapping and adhering to the surface of the recording material occurs.

That is, when printing is performed while moving (scanning) the printer head section including the ink head group 113 shown in FIG. When the color ink and the color ink are attached to adjacent areas on the surface of the recording material), as shown in FIGS.
Black ink applied area 114 with black ink attached to the surface of
And a color ink application region 126 to which color inks of cyan ink, magenta ink and yellow ink adhere later. FIG. 23 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the printer head unit in the direction of arrow 130 in FIG. FIG.
FIG. 4 is a schematic cross-sectional view taken along line 100-100 in FIG. At the boundary between the black ink application area 114 and the color ink application area 126, an overlap area 128 in which the black ink and the color ink permeate each other is formed. In the overlapping area 128, the color ink is applied after the black ink is applied.

Next, the ink head group 11 shown in FIG.
A case is considered in which printing is performed while scanning the printer head including the printer 3 in the direction of arrow 131. In this case, as shown in FIGS. 25 and 26, a black ink application area 114 and a color ink application area 123 are formed. FIG. 25 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the printer head unit in the direction of arrow 131 in FIG. FIG. 26 is a schematic cross-sectional view taken along line 100-100 in FIG. In the overlapping region 127 located between the black ink application region 114 and the color ink application region 123, the black ink is applied after the color ink is applied. Then, in the overlapping regions 128 and 127 (see FIGS. 23 to 26),
As described above, a difference occurs in the “black” color due to the difference in the application order between the black ink and the color ink. That is,
In order to further increase the printing speed, when using a bidirectional printing method in which the scanning direction of the printer head unit is any of the arrows 130 and 131 to print, if the scanning direction of the printer head unit is different, the same black Even in the print area, the color tone is different (color unevenness is generated), and there is a problem that the image quality of the resulting image is deteriorated. 23 to 26, the color ink application areas 126 and 123 are displayed in white or dots in consideration of the discrimination from the black ink application area 114. However, in actuality, cyan ink, magenta ink and The black color is obtained by applying the yellow ink repeatedly. Therefore, in FIGS. 23 and 25, the entire surface is actually printed in black.

In order to prevent the occurrence of color unevenness in the scanning direction of the printer head during printing as described above, for example, JP-A-7-19571 and JP-A-11-2168.
No. 82, as shown in FIG. 27, the cyan ink heads 110a and 110a are symmetrical with respect to the black ink head 109 in the ink head group 113.
b, a technique of arranging magenta ink heads 111a and 111b and yellow ink heads 112a and 112b is disclosed. FIG. 27 is a schematic diagram showing another example of the ink head group of the conventional printer.
When scanning the printer head section including the ink head group 113 shown in FIG. 27 in the direction of arrow 130, for example, a yellow ink head 112a, a magenta ink head 111a, a cyan ink head 110a, and a black ink head 109 are used. When scanning the printer head in the direction of arrow 131, the yellow ink head 112b, the magenta ink head 111b, the cyan ink head 110b, and the black ink head 109 are used.
With this configuration, it is possible to prevent the problem that the application order of the color ink and the black ink is different for each scanning direction as described above. However, in the ink head group shown in FIG. 27, the number of ink heads is doubled as compared with the related art, and the manufacturing cost of the printer increases. Therefore, it was difficult to apply the ink head group as shown in FIG. 27 to a relatively inexpensive printer.

As described above, conventionally, it has been difficult to improve the printing speed and prevent deterioration of the image quality of the formed image, and to realize a low-cost printer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to improve printing speed, prevent deterioration of the quality of an image formed, and reduce the cost. It is to provide a printer.

[0018]

A printer according to one aspect of the present invention is a printer that forms a print or an image by attaching ink to a surface of a recording material,
A color ink head group and a black ink head are provided. The color ink head group includes an ink head for attaching yellow ink to the surface of the recording material, an ink head for attaching magenta ink to the surface of the recording material, and an ink head for attaching cyan ink to the surface of the recording material. The black ink head causes black ink to adhere to the surface of the recording material. The black ink head is selected from a group of color ink heads, and is disposed between two ink heads that attach inks of different colors to the surface of the recording material.

With this arrangement, the printer head section including the color ink head group and the black ink head is moved with respect to the recording material along the direction in which the color ink head group and the black ink head are arranged (scanning direction). When forming a print or an image (performing bidirectional printing) on both the forward and backward passes of the scanning while relatively moving (scanning), it is attached to the recording material on both the forward and backward passes of the scan. The order of the inks can be the order of color ink, black ink, and color ink.
For this reason, in an overlapping area where the black ink and the color ink overlap, such as a boundary area between the area where the black ink is applied and the area where the color ink is applied, whether the printing is performed in the forward pass or the return pass of the scanning, Alternatively, the order of ink application can always be the order of color ink, black ink, and color ink. As a result, it is possible to reduce a difference in color tone due to the moving direction of the printer head in such an overlapping area. Thus, the printing speed can be improved by using the bidirectional printing method, and an image with good image quality can be obtained.

Further, since the black ink heads are arranged between the color ink heads so that the application order of the inks is the color ink, the black ink, and the color ink, the number of ink heads is not increased as compared with the prior art. For this reason, the number of ink heads in the printer head unit can be reduced as compared with the case where two sets of color ink heads are prepared for each of the forward and backward scans of the printer head unit in order to fix the order of ink application. . For this reason, it is possible to prevent an increase in the manufacturing cost of the printer, so that it can be easily applied to a low-priced printer.

In the printer according to the above aspect, the two color ink heads are preferably an ink head for attaching magenta ink to the surface of the recording material and an ink head for attaching cyan ink to the surface of the recording material.

In this case, the difference in the color tone of the overlapping area in the forward and backward scanning paths of the printer head is reduced as compared with the case where both the magenta ink head and the cyan ink head are arranged on one side of the black ink head. can do. As a result, it is possible to further reduce the occurrence of color unevenness in each moving direction of the printer head. This is for the following reasons. That is, if the magenta ink head and the cyan ink head are arranged on one side and the yellow ink head is arranged on the other side with respect to the black ink head, for example, on the outward path of the scanning of the printer head, the black ink head Magenta ink and cyan ink are applied, and yellow ink is applied on black ink on the return path (Case 1). On the other hand, for example, if a cyan ink head is arranged on one side with respect to a black ink head, and a magenta ink head and a yellow ink head are arranged on the other side, the cyan ink will be on the black ink on the outward scan of the printer head. After the application, the magenta ink and the yellow ink are applied on the black ink on the return path (case 2). At this time, the difference between the hue of the overlap area of the forward path (the area where magenta ink and cyan ink are applied on black ink) and the overlap area of the return path (the area where yellow ink is applied on black ink) in Case 1 is larger than the difference between the shades.
In Case 2, the difference in hue between the overlapping area on the outward path (area where cyan ink is applied on black ink) and the overlapping area on the return path (area where magenta ink and yellow ink are applied on black ink) is small. This is because the so-called color density (brightness) difference between the mixed color of the magenta ink and the yellow ink and the cyan ink is smaller than the so-called color density difference between the mixed color of the magenta ink and the cyan ink and the yellow ink. is there.

Preferably, the printer according to the above aspect further comprises a scanning means for scanning the black ink head and the group of color ink heads in a scanning direction parallel to the surface of the recording material. The head is preferably arranged along the scanning direction.

With this arrangement, when printing is performed while scanning the printer head section including the black ink head and the color ink head in the scanning direction, the order of ink application is the order of color ink, black ink, and color ink. Can be set reliably. As a result, it is possible to reduce the difference in the color tone in the overlapping area of the printing surface in the forward and backward scans, and to improve the image quality of the formed image.

A printer according to another aspect of the present invention includes:
A printer for forming a print or an image by attaching ink to a surface of a recording material, comprising a color ink head group and first and second black ink heads. The color ink head group includes an ink head for attaching yellow ink to the surface of the recording material, an ink head for attaching magenta ink to the surface of the recording material, and an ink head for attaching cyan ink to the surface of the recording material. The first and second black ink heads are arranged so as to sandwich the color ink head group, and make the black ink adhere to the surface of the recording material.

With this arrangement, when the printer head section including the color ink head group and the first and second black ink heads is caused to scan the surface of the recording material, the scanning is performed for each scanning direction (forward scan and For each return trip)
If one of the first black ink head and the second black ink head is used, the application order of the color ink and the black ink can be the same in both the forward path and the backward path of scanning. As a result, it is possible to reduce the difference in the hue in the overlapping area between the black ink and the color ink in the forward path and the backward path of scanning.

Further, as compared with the conventional printer head unit, the printer head unit according to the present invention has only one additional black ink head, so that it is possible to suppress an increase in the manufacturing cost of the printer.

In the printer according to the above another aspect, the first
And a scanning unit for scanning the second black ink head and the color ink head group in a scanning direction parallel to the surface of the recording material. The color ink head group and the first and second black ink heads may be further provided. Is preferably arranged along the scanning direction.

In this way, when printing is performed while scanning the printer head, the application order of the black ink and the color ink can be reliably set. As a result, it is possible to reliably prevent the occurrence of a color difference on the print surface for each scanning direction. For this reason, the image quality of the formed image can be improved.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

(Embodiment 1) FIG. 1 is a schematic perspective view showing Embodiment 1 of a printer according to the present invention. The printer will be described with reference to FIG.

Referring to FIG. 1, the printer 1 includes a carriage 2, a shaft 3, a belt 4, pulleys 5a and 5b, a drive motor 6, and a platen 8. The carriage 2 holds a printer head unit including an ink head having a plurality of nozzles for discharging ink. The carriage 2 is a shaft 3
Are slidably supported in the axial direction. Two pulleys 5a and 5b are installed near both ends of the shaft 3. The pulley 5a is connected to the drive shaft of the drive motor 6. A belt 4 is stretched between the pulleys 5a and 5b. This belt 4 is partially connected to the carriage 2. The pulley 5a is rotated by the rotation of the drive shaft of the drive motor 6, and the carriage 2 is slidable in the axial direction of the shaft 3 via the belt 4 by the rotation of the pulley 5a. A platen 8 is arranged below the carriage 2. The recording material 7 such as paper is supplied onto the platen 8. The carriage 2 is arranged at a predetermined distance from the recording material 7 supplied on the platen 8. Then, the belt 4 is driven by the drive motor 6 described above.
, The carriage 2 slides in the axial direction of the shaft 3 so that the carriage 2 is scanned in a direction substantially parallel to the surface of the recording material 7 and in a scanning direction parallel to the shaft 3 during printing. The shaft 3, the belt 4, the pulleys 5a and 5b, and the drive motor 6 constitute a scanning mechanism as scanning means.

The drive motor 6 is rotatable in both forward and reverse directions based on a signal for controlling the direction of the carriage 2 in the scanning direction. Further, a position detecting means (not shown) is provided on the carriage 2. And
The position detecting means generates a position signal for determining a printing position or a scanning range as the carriage 2 moves.

A printer head having an ink head for attaching yellow ink, magenta ink, cyan ink, and black ink to the recording material 7 is provided on the carriage 2. These ink heads are arranged along the scanning direction of the carriage 2. The ink heads are arranged in an array as shown in FIG. FIG. 2 is a schematic diagram showing an example of the arrangement of ink heads in the printer shown in FIG.

Referring to FIG. 2, the ink head group 13 of the printer head unit installed on the carriage 2 includes a cyan (C) ink head 10 for attaching cyan ink to the surface of the recording material 7, and a magenta ink head. A magenta (M) ink head 11 which is an ink head for attaching ink to the surface of the recording material 7 and a yellow (Y) which is an ink head for attaching yellow ink to the surface of the recording material
A color ink head group including an ink head 12 and a black (K) ink head 9 for attaching black ink to the surface of a recording material are provided. In the ink head group 13, the respective ink heads are arranged in the order of arrows 30 and 31 which are the scanning direction of the carriage 2 in the order of the cyan ink head 10, the magenta ink head 11, the black ink head 9 and the yellow ink head 12. Are located. That is, the black ink head 9 is a magenta ink head 11 which is selected from a group of color ink heads and is two ink heads for attaching inks of different colors to the surface of the recording material.
And the yellow ink head 12.
Cyan ink head 10, magenta ink head 11,
The respective ink heads such as the black ink head 9 and the yellow ink head 12 have the same configuration except for the color of the ink and the nozzle characteristics according to the ink. Each ink head has a nozzle for discharging a plurality of inks. These nozzles are arranged in one or a plurality of rows in a direction orthogonal to the arrows 30 and 31 that are the scanning direction of the carriage 2.
Then, a nozzle for ejecting ink is selected in accordance with an output signal from a computer or the like connected to the printer, and ink is adhered to the surface of the recording material 7 from the selected nozzle, whereby Print or form (print) an image. The printer 1 achieves a higher printing speed by adopting a bidirectional printing method that performs printing even when the carriage 2 is scanned in any of the directions of the arrow 30 and the arrow 31. .

The carriage 2 holding the printer head unit having the ink head group 13 shown in FIG.
, The order of application of the ink applied to the recording material 7 is the order of cyan ink, magenta ink, black ink, and yellow ink. When the carriage 2 is scanned in the direction of the arrow 31, ink is applied to the recording material 7 in the order of yellow ink, black ink, magenta ink, and cyan ink.

Consider a case where a black print area is printed by the printer 1 having the ink head group 13 shown in FIG.
At this time, in order to improve the drying property of the ink in the black printing area, the dot density of the black ink is reduced in the black printing area, and the color ink is applied to the gaps between the dots of the black ink. FIG. 3 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 shown in FIG. FIG. 4 shows a line segment 100-1 in FIG.
It is a cross section schematic diagram in 00. In FIG. 3, the entire surface is basically a black print surface. However, for convenience of explanation, a region where black display is performed by overlapping application of color inks is displayed as white instead of black. Referring to FIGS. 3 and 4, first, a yellow ink, which is a color ink, is applied from the yellow ink head 12 to the surface of the recording material 7. As a result, the recording material 7 has a yellow ink applied area 1 which is an area where the yellow ink has been applied.
5 are formed. Next, black ink is applied to the surface of the recording material 7 from the black ink head 9. As a result, a black ink applied area 14 which is an area to which the black ink is applied is formed. The yellow ink region 15 and the black ink region 14 are arranged so as to be adjacent to each other. Next, magenta ink and cyan ink are applied to the surface of the recording material 7 from the magenta ink head 11 and the cyan ink head 10, respectively. The magenta ink and the cyan ink are applied to the same position as the above-mentioned yellow ink area 15. As a result, a magenta / cyan ink application area 16 which is an area where the magenta ink and the cyan ink are applied is formed.

At this time, the black ink area 14 and magenta
In an overlapping area 17 where the cyan ink area 16 and the yellow ink area 15 are overlapped, the ink is applied in the order of yellow ink, black ink, magenta ink, and cyan ink.

Next, a case where printing is performed while scanning the carriage 2 in the direction of the arrow 30 will be considered. In this case, the recording material 7
Are applied in order of cyan ink, magenta ink, black ink and yellow ink. FIG. 5 is a schematic diagram of the printing surface in this case. FIG. 5 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. FIG. 6 is a schematic cross-sectional view taken along line 100-100 in FIG. Referring to FIGS. 5 and 6, first, a magenta / cyan ink applied area 16 which is an area to which the cyan ink and the magenta ink are applied is formed on the surface of the recording material 7.
Thereafter, a black ink is applied to an area adjacent to the magenta and cyan ink areas 16 to form a black ink applied area 14. Then, the yellow ink is applied to the area overlapping the magenta / cyan ink applied area 16, thereby forming the yellow ink applied area 15. In an overlapping area 18 where the magenta / cyan ink application area 16, the yellow ink application area 15, and the black ink application area 14 overlap, ink is applied in the order of cyan ink, magenta ink, black ink, and yellow ink. Have been.

As described above, the black ink head 9 is selected from the group of color ink heads, and the yellow ink head 12 and the magenta ink head 11 as two color ink heads for adhering inks of different colors to the surface of the recording material.
In any case where the scanning direction of the carriage 2 is the direction of the arrow 30 (forward path) or the direction of the arrow 31 (return path), the application order of the ink on the surface of the recording material 7 is color. The order is ink-black ink-color ink. For this reason, in the overlapping areas 17 and 18 where the color ink and the black ink overlap, the ink application order is as described above regardless of the scanning direction of the carriage 2. Can be reduced. As a result, when performing high-speed printing using the bidirectional printing method,
Deterioration of the formed image quality can be prevented.

The total number of ink heads of the printer according to the present invention is the same as the total number of ink heads in the ink head group 113 of the conventional printer shown in FIG. A printer can be realized.

Since the cyan ink head 10, the magenta ink head 11, the black ink head 9, and the yellow ink head 12 are arranged along the scanning direction of the carriage 2 as shown in FIG. By applying ink to the recording material 7 while the ink is being applied, the order of application of the ink can be reliably set in the order of color ink, black ink, and color ink.

Referring to FIGS. 3 and 5, since the color ink is always applied after the black ink is applied to the surface of the recording material 7, the black ink is applied last on the surface of the recording material 7. The area of the region can be made substantially constant regardless of the scanning direction. This makes it possible to further reduce the difference in the color tone of the printing surface depending on the scanning direction of the carriage 2.

(Embodiment 2) FIG. 7 is a schematic diagram showing an ink head group in a printer according to Embodiment 2 of the present invention. Embodiment 2 of the printer according to the present invention is as follows.
Basically, it has the same structure as the first embodiment of the present invention, but differs in the arrangement of the ink head group 13 shown in FIG.
The ink head group will be described with reference to FIG.

Referring to FIG. 7, the ink head group 13 includes:
Basically, it has the same structure as the ink head group shown in FIG. 2, but the arrangement order of the ink heads is different. That is, in the ink head group 13 in FIG.
The ink heads are arranged in the order of cyan ink head 10, black ink head 9, magenta ink head 11, and yellow ink head 12. In the printer including the ink head group 13 shown in FIG.
FIG. 8 shows the surface of the recording material when black printing is performed on the surface of the recording material 7 while scanning the carriage 2 in the direction 1. In this case, as in Embodiment 1 of the present invention, in order to improve the drying property of the ink in the black printing area, the dot density of the black ink is reduced in the black printing area, and Ink is applied. FIG.
7 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 in FIG. 7, and corresponds to FIG. FIG. 9 is a schematic cross-sectional view taken along line 100-100 in FIG.

Referring to FIGS. 8 and 9, first, a yellow / magenta ink application area 19 to which yellow ink and magenta ink are applied is formed on the surface of recording material 7.
Next, a black ink application area 1 in which black ink is applied to an area adjacent to the yellow / magenta ink application area 19
4 are formed. Thereafter, the cyan ink is applied so as to overlap the yellow and magenta ink applied areas 19, thereby forming the cyan ink applied area 20. Here, in the overlapping area 21, ink is applied in the order of yellow ink, magenta ink, black ink, and cyan ink.

Next, consider the case where black printing is performed on the surface of the recording material 7 while scanning the carriage 2 in the direction of arrow 30. In this case, as shown in FIGS. 10 and 11, a cyan ink application area 20 is first formed on the surface of the recording material 7. Thereafter, a black ink application area 14 where black ink is applied is formed in an area adjacent to the cyan ink application area 20. Then, a yellow / magenta ink application area 19 where magenta ink and yellow ink are applied so as to overlap the cyan ink application area 20 is formed. FIG.
0 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. FIG. 11 is a schematic cross-sectional view taken along line 100-100 in FIG. In the overlapping area 22 where the color ink and the black ink overlap, ink is applied in the order of cyan ink, black ink, magenta ink, and yellow ink.

Here, the difference in the so-called color density (brightness) between the mixed color of the magenta ink and the yellow ink and the cyan ink is based on the difference in the so-called color density between the mixed color of the magenta ink and the cyan ink and the yellow ink. small. For this reason, the difference in color between the overlapping region 17 (the region where the magenta ink and the cyan ink are applied on the black ink) and the overlapping region 18 (the region where the yellow ink is applied on the black ink) in the first embodiment of the present invention. Than in FIG.
When the ink head arrangement shown in FIG. 1 is used, the color of the overlap region 21 (the region where the cyan ink is applied on the black ink) and the overlap region 22 (the region where the magenta ink and the yellow ink are applied on the black ink) Can be reduced. For this reason, in the second embodiment of the present invention, in addition to the effects obtained by the first embodiment of the present invention, the carriage 2 having the tint in the overlapping portions 21 and 22 is provided.
Since the difference due to the scanning direction can be further reduced,
The image quality of printing can be further improved.

(Embodiment 3) Embodiment 3 of the printer according to the present invention basically has the same structure as that of the printer according to Embodiment 1 of the present invention. This is different from the printer in the first embodiment. FIG. 12 is a schematic diagram showing an ink head group in Embodiment 3 of the printer according to the present invention. FIG.
The ink head group will be described with reference to FIG.

Referring to FIG. 12, ink head group 13
Are black ink heads 9a and 9b as first and second black ink heads for attaching black ink to the surface of a recording material.
And a cyan ink head 10 serving as an ink head for attaching cyan ink to the surface of the recording material, a magenta ink head 11 serving as an ink head for attaching magenta ink to the surface of the recording material, and yellow ink being attached to the surface of the recording material. And a color ink head group including a yellow ink head 12 as an ink head. The black ink heads 9a and 9b are arranged so as to sandwich the color ink head group. The black ink heads 9a and 9b and the color ink head group are arranged along the scanning direction as in the first and second embodiments of the present invention.

A case where a black print area is printed by a bidirectional printing method using a printer having a printer head having such an ink head group 13 will be considered. In this case, as in Embodiments 1 and 2 of the present invention, in order to improve the drying property of the ink in the black printing area, the dot density of the black ink is reduced in the black printing area, and the gap between the dots of the black ink is Is applied. When the carriage 2 of the printer is scanned, for example, in the direction of arrow 31, the yellow ink head 12, the magenta ink head 11, the cyan ink head 10, and the black ink head 9
Use a. The scanning direction of the carriage 2 is indicated by an arrow 30.
, The cyan ink head 10, the magenta ink head 11, the yellow ink head 12, and the black ink head 9b are used. In this way, the black ink can be applied to the recording material 7 after the color ink is applied to the recording material 7 regardless of whether the scanning direction of the carriage is the arrow 30 or the arrow 31.

That is, as shown in FIGS. 13 and 14,
When the scanning direction is the direction of the arrow 31, first, the area 23 to which the yellow ink, the magenta ink, and the cyan ink are applied is formed on the surface of the recording material 7. And
Thereafter, the black ink ejected from the black ink head 9a is applied to the surface of the recording material 7 to form a black ink application area 14. Therefore, in the overlapping area 27, the black ink is applied after the color ink. FIG. 13 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 in FIG. 12, and FIG. 14 is a schematic cross-sectional view taken along line 100-100 in FIG. is there.

On the other hand, when the carriage 2 is scanned in the direction of arrow 30 in FIG. 12, ink is recorded from the cyan ink head 10, the magenta ink head 11, and the yellow ink head 12, as shown in FIGS. By applying the ink on the surface of the recording material 7, an area 24 to which the cyan ink, the magenta ink, and the yellow ink are applied is formed on the surface of the recording material 7. Next, black ink is applied to the surface of the recording material 7 from the black ink head 9b to form a black ink application area 14. FIG.
FIG. 16 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. 12, and FIG. 16 is a schematic cross-sectional view taken along line 100-100 in FIG. Then, in the overlapping area 27, as in the case of FIG. 14, the black ink is applied after the cyan ink, the magenta ink, and the yellow ink are applied. Therefore, the scanning direction is indicated by arrow 3
1 or the direction of the arrow 30, the area of the area where the black ink was last applied can be made almost the same as shown in FIGS. The difference can be reduced. As a result, at the same time as performing high-speed printing, it is possible to reliably prevent the image quality of the printed image from deteriorating.

In the printing process described with reference to FIGS. 13 to 16, the black ink is applied to the surface of the recording material 7 after the color ink is applied first. After applying to the surface, color ink may be applied. For example, referring to FIG.
When the carriage 2 is scanned in the direction 1, black ink is first applied to the surface of the recording material 7 from the black ink head 9 b, and then color ink is applied from the yellow ink head 12, the magenta ink head 11, and the cyan ink head 10. 7 is applied to the surface. On the other hand, if the scanning direction is arrow 3
If the direction is the direction indicated by 0, first, the black ink head 9a
After the black ink is applied to the surface of the recording material 7, color ink is applied to the surface of the recording material 7 from the cyan ink head 10, the magenta ink head 11, and the yellow ink head 12.

FIGS. 17 and 18 show the printing surface of the recording material 7 when the scanning direction is the direction shown by the arrow 31 as described above. FIG. 17 is an enlarged schematic plan view showing a printing surface according to a modification of the printer according to the third embodiment of the present invention. FIG. 18 is a schematic sectional view taken along line 100-100 in FIG. FIGS. 17 and 18 show FIGS.
Respectively. Then, as described above, first, the black ink is applied, and then the color ink is applied. Therefore, in the overlapping area 28, the yellow ink, the magenta ink, and the cyan ink are applied in an overlapping manner after the black ink is applied. It is in a state.

FIGS. 19 and 20 show the printing surface of the recording material 7 when the scanning direction is the direction shown by the arrow 30 as described above. FIG. 19 is an enlarged schematic plan view showing a printing surface according to a modification of the printer according to the third embodiment of the present invention, and shows a printing surface when black ink is applied first while scanning the carriage 2 in the direction of arrow 30. . FIG.
0 is a schematic sectional view taken along line 100-100 in FIG. 19 and 20 correspond to FIGS. 15 and 16, respectively. Referring to FIGS. 19 and 20, in this case as well, in the overlapping area 28, the black ink is applied, and then the yellow ink, the magenta ink, and the cyan ink are applied in a superimposed manner. That is, regardless of whether the scanning direction of the carriage 2 is the direction of the arrow 31 or the direction of the arrow 30, the overlapping area 28 is in a state where the color ink is applied on the black ink. For this reason, the same effects as those shown in FIGS. 13 to 16 can be obtained.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0058]

As described above, according to the present invention, even if high-speed printing is performed by employing the bidirectional printing method, an image of sufficient image quality can be formed at low cost without doubling the number of ink heads. Can be. Further, according to the present invention, it is possible to improve the drying property of the ink in the black print area on the recording material by using a technique such that the pigment black ink and the dye color ink are superimposed or printed adjacently. When the printing speed is improved by using the bidirectional printing method, the image quality of the black print area can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of a printer according to the present invention.

FIG. 2 is a schematic diagram showing an example of an arrangement of ink heads in the printer shown in FIG.

FIG. 3 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 shown in FIG. 2;

FIG. 4 is a schematic sectional view taken along line 100-100 in FIG. 3;

FIG. 5 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. 2;

FIG. 6 is a schematic sectional view taken along line 100-100 in FIG. 5;

FIG. 7 is a schematic diagram illustrating an ink head group in a printer according to a second embodiment of the present invention.

8 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 in FIG. 7;

FIG. 9 is a schematic sectional view taken along line 100-100 in FIG. 8;

10 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. 7;

11 is a schematic cross-sectional view taken along line 100-100 in FIG.

FIG. 12 is a schematic diagram illustrating an ink head group in a printer according to a third embodiment of the present invention.

13 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 31 in FIG. 12;

FIG. 14 is a schematic sectional view taken along line 100-100 in FIG.

15 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the carriage in the direction of arrow 30 in FIG. 12;

16 is a schematic sectional view taken along line 100-100 in FIG.

FIG. 17 is an enlarged schematic plan view showing a printing surface according to a modification of the printer according to the third embodiment of the present invention.

FIG. 18 is a schematic sectional view taken along line 100-100 in FIG. 17;

FIG. 19 is an enlarged schematic plan view showing a printing surface according to a modification of the printer according to the third embodiment of the present invention.

20 is a schematic sectional view taken along line 100-100 in FIG. 19;

FIG. 21 is a schematic diagram illustrating an ink head group of a conventional printer.

FIG. 22 shows another ink head group of a conventional printer.
It is a schematic diagram which shows two examples.

23 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the printer head in the direction of arrow 130 in FIG. 21.

FIG. 24 is a schematic sectional view taken along line 100-100 in FIG.

25 is an enlarged schematic plan view showing a printing surface when printing is performed while scanning the printer head unit in the direction of arrow 131 in FIG. 21.

FIG. 26 is a schematic sectional view taken along line 100-100 in FIG.

FIG. 27 shows another ink head group of a conventional printer.
It is a schematic diagram which shows two examples.

[Explanation of symbols]

1 printer, 2 carriages, 3 shafts, 4 belts, 5a, 5b pulley, 6 drive motor, 7 recording material, 8 platen, 9, 9a, 9b black ink head,
10 cyan ink head, 11 magenta ink head, 12 yellow ink head, 13 ink head group, 14 black ink application area, 15 yellow ink application area, 16 magenta / cyan ink application area, 1
7, 18, 21, 22, 27, 28 overlap area, 19
Yellow and magenta ink applied area, 20 cyan ink applied area, 23, 25 Yellow and magenta ink and cyan ink applied area, 24, 26
Areas where cyan ink, magenta ink and yellow ink are applied, 30, 31 arrows.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Takuji Honto F-term (reference) 2C056 EA01 EA11 EA24 EC65 EC75 EC79 EE03 EE10 EE14 FA11 HA07 in 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka

Claims (5)

[Claims] 1. A printer for forming a print or an image by depositing ink on a surface of a recording material, comprising: an ink head for depositing yellow ink on the surface of the recording material; and a magenta ink on the surface of the recording material. A color ink head group consisting of an ink head that causes the ink to adhere to the surface of the recording material, and a black ink head that adheres the black ink to the surface of the recording material. A printer, which is selected from a group of color ink heads and is disposed between two ink heads for applying inks of different colors to a surface of a recording material. 2. The printer according to claim 1, wherein said two ink heads are an ink head for attaching magenta ink to the surface of the recording material and an ink head for attaching cyan ink to the surface of the recording material. 3. A scanning unit for scanning the black ink head and the color ink head group in a scanning direction parallel to a surface of a recording material, wherein the two ink heads and the black ink head are in the scanning direction. The printer according to claim 1, wherein the printer is arranged along the line. 4. A printer for forming a print or an image by adhering ink to a surface of a recording material, comprising: an ink head for adhering yellow ink to the surface of the recording material; and a magenta ink adhering to the surface of the recording material. A color ink head group including an ink head to be applied and an ink head to attach cyan ink to the surface of the recording material; and a first ink unit arranged to sandwich the color ink head group and attaching black ink to the surface of the recording material. And a second black ink head. 5. A scanning device for scanning the first and second black ink heads and the color ink head group in a scanning direction parallel to the surface of a recording material, wherein the color ink head group and the first The printer according to claim 4, wherein the second black ink head and the second black ink head are arranged along the scanning direction.